Printing apparatus and a method therefor, and information processing apparatus and a method therefor

ABSTRACT

A printing apparatus includes an output unit for providing a printout by generating output information from input information received from an information processing apparatus, and a power consumption control unit for controlling power consumption of the entire printing apparatus by controlling electric power supply to the output unit based on information received from the information processing apparatus. An information outputting apparatus includes an output unit for outputting information to an output apparatus using a wire system or a radio system, and a control unit for controlling the output unit by switching between the wire system and the radio system in accordance with a transmission/reception relationship between an information processing apparatus and the output apparatus.

This application is a continuation of application Ser. No. 08/755,132filed Nov. 22, 1996 now abandoned, which is a continuation ofapplication Ser. No. 08/163,757, filed Dec. 9, 1993, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a printing apparatus and a method therefor, inwhich input information, comprising control codes, character codes andthe like, is received from an information processing apparatus, such asa host computer or the like, and output information is generated andoutput.

The invention also relates to an information processing apparatus, suchas a host computer or the like, and a method therefor, for outputtinginput information, comprising control codes, character codes and thelike, and commands are output to an output apparatus, such as a printingapparatus or the like.

2. Description of the Related Art

Printing systems have been known in which printing is performed bytransmitting data by a radio system from an information processingapparatus, such as a host computer or the like, to a printing apparatus.FIG. 29 shows the configuration of such a radio communication apparatusand a conventional printing system utilizing the apparatus. In FIG. 29,host computer 1 transmits printing data to printing apparatus 4.Reference numeral 2 represents a transmission/reception block at theside of host computer 1, and reference numeral 3 represents atransmission/reception block at the side of printing apparatus 4.Printing apparatus 4 prints an image on a recording medium, such asrecording paper or the like, based on the printing data received fromhost computer 1.

In transmission/reception block 2, reference numeral 6-1 represents atransmission/reception unit for exchanging data, commands, statusinformation and the like with host computer 1. Transmission/receptionunit 6-1 modulates a signal from host computer 1 and transmits theresultant signal to antenna 26-1, or inputs a modulated signal receivedby antenna 26-1, demodulates the signal, and transmits the resultantsignal to host computer 1. Power supply unit 7-1 applies a DC voltage totransmission/reception unit 6-1. An AC voltage is applied to powersupply unit 7-1 via AC receptacle 5-1 and power switch 8-1.Transmission/reception block 3 at the side of printing apparatus 4 alsohas the same configuration. Printing apparatus 4 also includes powersupply unit 10 for applying a DC voltage to circuitry within theapparatus. An AC voltage is applied to power supply unit 10 via ACreceptacle 5-3 and power switch 8-3.

In the above-described conventional system, a power supply unit and apower switch are provided in each of the blocks 2 and 3, and printingapparatus 4. Hence, when starting the printing system, the operator mustgo to the places where the respective apparatuses are installed, andturn on or off power switches of the respective apparatuses. Such astarting operation is very troublesome especially when host computer 1and printing apparatus 4 are installed at separate places.

A printing apparatus of this kind is designed assuming that the user ispresent in the vicinity of the printing apparatus, whether it isoperated by a wire system or by a radio system. Hence, the power supplyof the apparatus is controlled in such a way that the user performs adirect physical operation of the power switch and the like of theapparatus.

In the above-described conventional approach, especially when aplurality of information processing apparatuses are connected to theprinting apparatus, or when the printing apparatus is not in thevicinity of the information processing apparatuses, as in a networkenvironment, power is, in many cases, always supplied to the powersupply of the printing apparatus even if the apparatus is not beingused.

In such a case, the ratio of power consumption in a standby state to thetotal power consumption of the apparatus has a large value, causing aproblem from the viewpoint of energy saving.

Furthermore, when a plurality of information processing apparatuses areconnected to the printing apparatus by a radio (a system using a radioinformation transceiver), for some apparatuses, and by a wire system (asystem using interface cables), for other apparatuses, the informationprocessing apparatus side cannot output information to the printingapparatus and the like by switching between the radio system and thewire system in accordance with the system environment.

SUMMARY OF THE INVENTION

It is an object of the present invention to control power consumption ofthe entire printing apparatus based on received information.

According to one aspect, the present invention which achieves thisobject relates to a printing apparatus comprising output means forproviding a printout by generating output information from inputinformation received from an information processing apparatus, and powerconsumption control means for controlling power consumption of theentire printing apparatus by controlling electric power supply to theoutput means based on information received from the informationprocessing apparatus.

According to another aspect, the present invention which achieves thisobject relates to a printing method which controls power consumption ofthe entire printing apparatus by controlling electric power supply tooutput means, for providing a printout by generating output informationfrom input information received from an information processingapparatus, based on information received from the information processingapparatus.

It is a further object of the present invention to detect a receptionstatus of received information, and control power consumption of theentire printing apparatus based on a result of the detection.

According to one aspect of this further object, the present inventionwhich achieves this object relates to a printing apparatus comprisingoutput means for providing a printout by generating output informationfrom input information received from an information processingapparatus, detection means for detecting a status of informationreception from the information processing apparatus, and powerconsumption control means for controlling power consumption of theentire printing apparatus by controlling electric power supply to theoutput means based on a result of the detection by the detection means.

According to another aspect of this further object, the presentinvention which achieves this object relates to a printing method whichdetects a status of information reception from an information processingapparatus, and controls power consumption of the entire printingapparatus by controlling electric power supply to output means, forproviding a printout by generating output information from inputinformation received from the information processing apparatus, based ona result of the detection processing.

It is a still further object of the present invention to interruptelectric power supply when input information has not been received for apredetermined time period.

According to one aspect of this further object, the present inventionwhich achieves this object relates to a printing apparatus comprisingoutput means for providing a printout by generating output informationfrom input information received from an information processingapparatus, and power supply control means for interrupting electricpower supply to the output means when input information has not beenreceived from the information processing apparatus for a predeterminedtime period.

According to another aspect of this still further object, the presentinvention which achieves this object relates to a printing method whichinterrupts electric power supply to the output means, for providing aprintout by generating output information from input informationreceived from an information processing apparatus, when inputinformation has not been received from the information processingapparatus for a predetermined time period.

It is still another object of the present invention to start electricpower supply when input information has been received in a state inwhich electric power supply is interrupted.

According to one aspect of this object, the present invention relates toa printing apparatus comprising output means for providing a printout bygenerating output information from input information received from aninformation processing apparatus, and power supply control means forstarting electric power supply to the output means when the inputinformation has been received from the information processing apparatusin a state in which electric power supply to the output means isinterrupted.

According to another aspect of this object, the present inventionrelates to a printing method which starts electric power supply tooutput means, for providing a printout by generating output informationfrom input information received from an information processingapparatus, when the input information has been received from theinformation processing apparatus in a state in which electric powersupply to the output means is interrupted.

It is still a further object of the present invention to outputinformation to an output apparatus by switching between a wire systemand a radio system in accordance with a transmission/receptionrelationship.

According to one aspect of this further object, the present inventionwhich achieves this object relates to an information processingapparatus comprising output means for outputting information to anoutput apparatus using a wire system or a radio system, and controlmeans for controlling the output means by switching between the wiresystem and the radio system in accordance with a transmission/receptionrelationship between the information processing apparatus and the outputapparatus.

According to another aspect of this further object, the presentinvention which achieves this object relates to an informationprocessing method which determines a transmission/reception relationshipbetween an information processing apparatus and an output apparatus, andoutputs information to the output apparatus by switching between a wiresystem and a radio system in accordance with a result of thedetermination.

The foregoing and other objects, advantages and features of the presentinvention will become more apparent from the following description ofthe preferred embodiments taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a schematic configuration of aprinting system according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating the operation of command-statustransmission/reception unit 24 of transmission/reception block 12 shownin FIG. 1;

FIG. 3 is a block diagram illustrating a schematic configuration of aprinting system according to another embodiment of the presentinvention;

FIG. 4 is a flowchart illustrating the operation of command/statustransmission/reception unit 24 of transmission/reception block 12 shownin FIG. 3;

FIG. 5 is a flowchart illustrating the operation of command/statustransmission/reception unit 34 of transmission/reception block 13 shownin FIG. 3;

FIG. 6 is a flowchart illustrating the operation of command/statustransmission/reception unit 46 of printer 14 shown in FIG. 3;

FIG. 7 is a block diagram illustrating a schematic configuration of aprinting system according to still another embodiment of the presentinvention;

FIG. 8 is a flowchart illustrating the operation of commandtransmission/reception unit 28 of transmission/reception block 12a shownin FIG. 7;

FIG. 9 is a flowchart illustrating the operation of commandtransmission/reception unit 38 of transmission/reception unit 13a shownin FIG. 7;

FIG. 10 is a flowchart illustrating the operation of command receptionunit 52 of printer 14a shown in FIG. 7;

FIG. 11 is a block diagram illustrating a schematic configuration of aprinting system according to still another embodiment of the presentinvention;

FIG. 12 is a flowchart illustrating the operation of power-on/offcommand transmission/reception unit 60 of transmission/reception block12b shown in FIG. 11;

FIG. 13 is a flowchart illustrating the operation of power-on/offcommand transmission/reception unit 62 of transmission/reception block13b shown in FIG. 11;

FIG. 14 is a flowchart illustrating the operation of power-on/offcommand reception unit 64 of printer 14b shown in FIG. 11;

FIG. 15 is a block diagram illustrating a schematic configuration of aprinting system according to still another embodiment of the presentinvention;

FIG. 16 includes block diagrams illustrating a specific configuration ofthe printing system shown in FIG. 3;

FIG. 17 is a flowchart illustrating the operation of host computer 1 or1' to be shown in FIG. 24;

FIG. 18 illustrates contents displayed on a CRT of the host computer;

FIG. 19 is a flowchart illustrating the operation of host computer 1 or1' shown in FIG. 24;

FIG. 20 illustrates contents displayed on the CRT of the host computer;

FIG. 21 is a flowchart illustrating the operation of host computer 1 or1' shown in FIG. 24;

FIG. 22 is a flowchart illustrating the operation of host computer 1 or1' shown in FIG. 24;

FIG. 23 illustrates contents displayed on the CRT of the host computer;

FIG. 24 is a diagram illustrating a system in which a host computer anda printer are connected by a wire system and a radio system;

FIG. 25 is a block diagram illustrating a configuration of control in aprinting system according to still another embodiment of the presentinvention;

FIG. 26 is a flowchart illustrating a first current supply controlprocedure in the printing system of the embodiment shown in FIG. 25;

FIG. 27 is a flowchart illustrating a second current supply controlprocedure in the printing system of the embodiment shown in FIG. 25;

FIG. 28 is a flowchart illustrating a third current supply controlprocedure in the printing system of the embodiment shown in FIG. 25;

FIG. 29 is a block diagram illustrating a schematic configuration of aconventional printing system;

FIG. 30 is a cross-sectional view illustrating the configuration of alaser-beam printer to which the present invention is applied; and

FIG. 31 shows an external appearance illustrating the configuration ofan ink-jet printer to which the present invention is applied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail with reference to the drawings.

FIG. 1 is a block diagram illustrating a schematic configuration of aprinting system according to a first embodiment of the presentinvention. In FIG. 1, the same units as those shown in FIG. 29 areindicated by the same reference numerals, and an explanation thereofwill be omitted.

In FIG. 1, reference numeral 12 represents a transmission/receptionblock at the side of host computer 1, and reference numeral 13represents a transmission/reception block at the side of printingapparatus 4. In transmission/reception block 12, datatransmission/reception block 21 modulates data from host computer 1 andtransmits the modulated data to antenna 26-1, or demodulates a modulatedsignal from antenna 26-1 and transmits the demodulated signal to hostcomputer 1. Main power supply unit 22 applies a DC voltage to datatransmission/reception unit 21. Power supply switch 23 switches on andoff an AC voltage applied to main power supply unit 22 in response tosignal 27 from command/status transmission/reception unit 24.Command/status transmission/reception unit 24 modulates command datafrom host computer 1 and outputs the modulated data to antenna 26-1, ordemodulates a modulated signal from antenna 26-1 and transmits thedemodulated signal to host computer 1 as status data. Sub-power supplyunit 25 applies a DC voltage to command/status transmission/receptionunit 24. An AC voltage is always applied to this sub-power supply unit25 via AC receptacle 5-1.

Power supply switch 23 is controlled by signal 27 from command/statustransmission/reception unit 24. When a command "turn on the power supplyof the radio apparatus" is transmitted from host computer 1, thiscommand is interpreted by command/status transmission/reception unit 24,and signal 27 is output as an "on" signal. Power supply switch 23 isthereby switched on. When a command "turn off the power supply of theradio apparatus" is transmitted from host computer 1, the command isinterpreted by command/status transmission/reception unit 24, and signal27 is output as an "off" signal, whereby power supply switch 23 isswitched off.

A power-supply-on/off command transmitted from host computer 1 is outputby antenna 26-1 after being modulated by command/statustransmission/reception unit 24, and is input to command/statustransmission/reception unit 34 within transmission/reception block 13 atthe side of printing apparatus 4. The configuration of thistransmission/reception block 13 is substantially the same as theconfiguration of the transmission/reception block 12 at the side of hostcomputer 1. That is, power is always supplied to command/statustransmission/reception unit 34 via sub-power supply unit 35, and powersupply switch 33 is switched on and off by making signal 36 an "on"signal and an "off" signal by power-supply-on/off commands from hostcomputer 1 received via antenna 26-2. When power supply switch 33 isswitched on, power is supplied from main power supply unit 32 to datatransmission/reception unit 31 to provide a state in which data fromhost computer 1 can be transmitted to printing apparatus 4 by a radiosystem.

FIG. 2 is a flowchart illustrating the operation of command/statustransmission/reception unit 24 of transmission/reception block 12. Adescription will be provided of the operation of command/statustransmission/reception unit 24 with reference to the flowchart shown inFIG. 2.

The operation program shown in the flowchart of FIG. 2 is stored in aROM (read-only memory) within command/status transmission/reception unit24, as illustrated in FIG. 16. A CPU (central processing unit) withincommand/status transmission/reception unit 24 controls the followingoperation based on this program. A RAM (random access memory) withincommand/status transmission/reception unit 24 is used as a work memoryand the like.

First, in step S1, the CPU determines if a command from host computer 1has been received within the RAM. If the result of the determination isaffirmative, the process proceeds to step S2, in which the command isreceived and analyzed. In step S3, the CPU determines if the receivedcommand is a command to control the power supply. If the result of thedetermination is negative, the process proceeds to step S4, in which acontrol corresponding to the received command is executed.

If the result of the determination in step S3 is affirmative, theprocess proceeds to step S5, in which the CPU determines if the commandis a command to turn on the power supply. If the result of thedetermination is affirmative, the process proceeds to step S6, in whichsignal 27 is output by making it an "on" signal. Main power supply unit22 is thereby turned on, whereby electric power is supplied to datatransmission/reception unit 21 to provide a state in which data fromhost computer 1 can be received. The process then proceeds to step S7,in which a power-supply-on signal is transmitted totransmission/reception block 13. Power supply switch 33 oftransmission/reception block 13 at the side of printing apparatus 4 isthereby switched on, so that data can be transmitted and receivedbetween transmission/reception blocks 13 and 12.

If the received command is determined to be a power-supply-off commandin step S5, the process proceeds to step S8, in which signal 27 is madeto be an "off" signal and is output to power supply switch 23. Powersupply switch 23 is thereby switched off, whereby main power supply unit22 is turned off. The process then proceeds to step S9, in which apower-supply-off signal is transmitted to transmission/reception block13. Power supply switch 33 is thereby switched off under the control ofcommand/status transmission/reception unit 34 in transmission/receptionblock 13 at the side of printing apparatus 4.

The operation of command/status transmission/reception unit 34 oftransmission/reception block 13 at the side of printing apparatus 4 canalso be described in the same manner as the operation shown in theflowchart of FIG. 2. That is, in step S1, the CPU determines if acommand from transmission/reception block 12 is present. If the commandis a command to turn on the power supply, signal 36 is made to be an"on" signal in step S6, and signal 36 to switch on power supply switch33 of main power supply unit 32 is output. If the command is a commandto turn off the power supply, signal 36 is output in step S8 switch offpower supply switch 33 of main power supply unit 32. The respectiveprocesses then proceed to step S10 without performing the processing ofsteps S7 and S9.

As described above, according to the first embodiment, the powersupplies of transmission/reception blocks 12 and 13 are automaticallyturned on by a command from host computer 1, so that data can betransmitted and received between host computer 1 and printing apparatus4.

By controlling the amount of electric power supply withintransmission/reception block 12 or 13, it is possible to control theamount of electric power consumption in the entiretransmission/reception block.

FIG. 3 is a block diagram illustrating a schematic configuration of aprinting system according to a second embodiment of the presentinvention. In FIG. 3, the same units as those shown in FIG. 1 areindicated by the same reference numerals, and an explanation thereofwill be omitted. In the second embodiment, printing apparatus (printer)14 is configured by providing command/status transmission/reception unit46 and sub-power supply unit 47 in addition to datatransmission/reception unit 41, so that the power supply of printingapparatus 14 can be automatically turned on by a power-supply-on commandfrom host computer 1.

The configuration of printing apparatus 14 will now be described withreference to FIG. 3. Data transmission/reception unit 41 performstransmission/reception of various kinds of data, such as printing dataand the like, with transmission/reception block 13. Main control unit42, comprising a CPU and the like, controls the entire printingapparatus 14. Memory 43 comprises a RAM for storing printing data inunits of a page, and for temporarily storing various kinds of data, anda ROM for storing control programs for the entire printing apparatus 14.Printer-engine control unit 44 controls the operation of printer engine45. A DC voltage is applied to the data transmission/reception unit 41,main control unit 42, memory 43, printer-engine control unit 44, printerengine 45 and the like from main power supply unit 48. An AC voltage isapplied to main power supply unit 48 via power supply switch 49 and ACreceptacle 5-3.

A "power-supply-on/off command" transmitted from host computer 1 viatransmission/reception blocks 12 and 13 is received by command/statustransmission/reception unit 46 of printing apparatus (printer) 14. Thecommand/status transmission/reception unit 46 controls signal 50 inaccordance with the contents of the power-supply-on/off command. Theswitching on and off of power supply switch 49 is controlled by thissignal 50. Main power supply unit 48 of printing apparatus 14 issubjected to on/off control by the power supply switch 49. Accordingly,by controlling electric power consumption of the entire printingapparatus 14, electric power consumption of printing apparatus 14 in astandby state (when a printing operation is not performed) can, forexample, be reduced.

FIG. 4 is a flowchart illustrating the operation of command/statustransmission/reception unit 24 of transmission/reception block 12 shownin FIG. 3. The operation of command/status transmission/reception unit24 will now be described with reference to the flowchart shown in FIG.4.

The program shown in the flowchart of FIG. 4 is stored in a ROM withincommand/status transmission/reception unit 24, as shown in FIG. 16. ACPU within command-status transmission/reception unit 24 controls thefollowing operation based on this program.

First, in step S11, the CPU determines if a command from host computer 1has been received within the RAM. If the result of the determination isaffirmative, the process proceeds to step S12, in which the command isreceived and analyzed. If the result of the determination in step S11 isnegative, the process proceeds from step S11 to step S20. In step S13,the CPU determines if the received command is a command to control thepower supply. If the result of the determination is negative, theprocess proceeds to step S14, in which a control corresponding to thereceived command is executed.

If the result of the determination in step S13 is affirmative, theprocess proceeds to step S15, in which the CPU determines if thereceived command is a command to turn on the power supply oftransmission/reception block 12. If the result of the determination isaffirmative, the process proceeds to step S16, in which signal 27 ismade to be an "on" signal to switch on switch 23, whereby main powersupply 22 is turned on to supply electric power to datatransmission/reception unit 21, so that data can be transmitted to andreceived from host computer 1 and transmission/reception block 13. Ifthe result of the determination in step S15 is negative, the processproceeds to step S17, in which the CPU determines if the receivedcommand is a command to turn off the power supply oftransmission/reception block 12. If the result of the determination isaffirmative, the process proceeds to step S18, in which signal 27 ismade to be an "off" signal to switch off switch 23, whereby main powersupply unit 22 is turned off.

If the result of the determination in step S17 is negative, that is, ifthe received command is a power-supply-on/off command fortransmission/reception block 13 or printer 14, the process proceeds tostep S19, in which the power-supply-on/off command fortransmission/reception block 13 or printer 14 is transmitted totransmission/reception block 13.

After the processing of step S14, S16, S18 or S19 has been completed,the process proceeds to step S20, in which the CPU determines if astatus transmission request from host computer 1 is present. If theresult of the determination is affirmative, the process proceeds to stepS21, in which status data of transmission/reception block 12 or 13, orprinter 14 is transmitted to host computer 1. If the result of thedetermination in step S20 is negative, the process returns to step S11,and the above-described processing is repeated.

Accordingly, the power supply of transmission/reception block 12 issubjected to on/off control in accordance with a command input from hostcomputer 1. The power supplies of transmission/reception block 13 andprinter 14 are also subjected to on/off control in accordance with thecommand input from host computer 1. Since electric power supply to therespective command/status transmission/reception units oftransmission/reception blocks 12 and 13 and printer 14 is maintained,the power supply control request from host computer 1 is achieved.

FIG. 5 is a flowchart illustrating the operation of command/statustransmission/reception unit 34 of transmission/reception block 13 shownin FIG. 3. The operation of command/status transmission/reception unit34 will be described with reference to the flowchart shown in FIG. 5.The program shown in this flowchart is stored in the ROM, and the CPUcontrols the following operation based on the program.

In step S31, the CPU determines if a command from transmission/receptionblock 12 has been received within the RAM. If the result of thedetermination is affirmative, the process proceeds to steps S32, andfurther to S33. If the result of the determination is negative, theprocess proceeds to step S40.

In step S33, the CPU determines if the received command is a powersupply control command. If the result of the determination is negative,the process proceeds to step S34. If the result of the determination isaffirmative, the process proceeds to step S35.

In step S35, the CPU determines if the received command is a command toturn on the power supply of transmission/reception block 13. If theresult of the determination is affirmative, the process proceeds to stepS36, in which signal 36 is made to be an "on" signal to switch on switch33, whereby main power supply unit 32 is turned on to supply electricpower to data transmission/reception unit 31, so that data can betransmitted to and received from transmission/reception block 12 andprinter 14. If the result of the determination in step S35 is negative,the process proceeds to step S37, in which the CPU determines if thereceived command is a command to turn off the power supply oftransmission/reception block 13. If the result of the determination isaffirmative, the process proceeds to step S38, in which signal 36 ismade to be an "off" signal to switch off switch 33, whereby main powersupply unit 32 is turned off.

If the result of the determination in step S37 is negative, that is, ifthe received command is a power-supply-on/off command for printer 14,the process proceeds to step S39, in which the power-supply-on/offcommand for printer 14 is transmitted to printer 14.

After the processing of step S34, S36, S38 or S39 has been completed,the process proceeds to step S40, in which the CPU determines if astatus transmission request from transmission/reception block 12 ispresent. If the result of the determination is affirmative, the processproceeds to step S41, in which requested status data oftransmission/reception block 13 or printer 14 is transmitted totransmission/reception block 12. If the result of the determination instep S40 is negative, the process returns to step S31, and theabove-described processing is repeated.

Accordingly, the power supply of transmission/reception block 13 issubjected to on/off control in accordance with a command input fromtransmission/reception block 12. The power supply of printer 14 is alsosubjected to on/off control in accordance with the command input fromtransmission/reception block 12. Since electric power supply to therespective command/status transmission/reception units oftransmission/reception blocks 13 and printer 14 is maintained, the powersupply control request input via transmission/reception block 12 isachieved.

FIG. 6 is a flowchart illustrating the operation of command/statustransmission/reception unit 46 of printer 14 shown in FIG. 3. Theoperation of command/status transmission/reception unit 46 will bedescribed with reference to the flowchart shown in FIG. 6. The programshown in this flowchart is stored in the ROM, and the CPU controls thefollowing operation based on the program.

In step S51, the CPU determines if a command from transmission/receptionblock 13 has been received within the RAM. If the result of thedetermination is affirmative, the process proceeds to steps S52, andfurther to S53. If the result of the determination is negative, theprocess proceeds to step S59.

In step S53, the CPU determines if the received command is a powersupply control command. If the result of the determination is negative,the process proceeds to step S54. If the result of the determination isaffirmative, the process proceeds to step S55.

In step S55, the CPU determines if the received command is a command toturn on the power supply of printer 14. If the result of thedetermination is affirmative, the process proceeds to step S56, in whichsignal 50 is made to be an "on" signal to switch on switch 49, wherebymain power supply unit 48 is turned on to supply electric power to datablock 40, so that printer 14 can transmit and receive data. If theresult of the determination in step S55 is negative, the processproceeds to step S57, in which the CPU determines if the receivedcommand is a command to turn off the power supply of printer 14. If theresult of the determination is affirmative, the process proceeds to stepS58, in which signal 50 is made to be an "off" signal to switch offswitch 49, whereby main power supply unit 48 is turned off. If theresult of the determination in step S57 is negative, the processproceeds to step S59.

After the processing of step S54, S56 or S58 has been completed, theprocess proceeds to step S59, in which the CPU determines if a statustransmission request from transmission/reception block 13 is present. Ifthe result of the determination is affirmative, the process proceeds tostep S60, in which status data of printer 14 is transmitted totransmission/reception block 13. If the result of the determination instep S59 is negative, the process returns to step S51, and theabove-described processing is repeated.

Accordingly, the power supply of printer 14 is subjected to on/offcontrol in accordance with a command input from transmission/receptionblock 13. Since electric power supply to command/statustransmission/reception unit 46 of printer 14 is maintained, the powersupply control request input via transmission/reception block 13 isachieved.

FIG. 7 is a block diagram illustrating a schematic configuration of aprinting system according to another embodiment of the presentinvention. In FIG. 7, the same units as those shown in FIG. 3 areindicated by the same reference numerals. In this embodiment, therespective data transmission/reception units 21, 31 and 41, and therespective command/status transmission/reception units 24, 34 and 46 ofthe transmission/reception blocks 12 and 13 and the printing apparatus14 are replaced by data/status transmission/reception units 29, 37 and51, and command transmission/reception units 28, 38 and 52,respectively. Main power supply units 22, 32 and 48 oftransmission/reception blocks 12a and 13a and printing apparatus 14a aresubjected to on/off control based on a command from host computer 1received via command transmission/reception units 28, 38 and 52,respectively.

FIG. 8 is a flowchart illustrating the operation of commandtransmission/reception unit 28 of transmission/reception block 12a shownin FIG. 7. The operation of command transmission/reception unit 28 willnow be described with reference to the flowchart shown in FIG. 8. Theprogram shown in the flowchart of FIG. 8 is stored in the ROM. The CPUcontrols the following operation based on this program.

First, in step S71, the CPU determines if a command from host computer 1has been received within the RAM. If the result of the determination isaffirmative, the process proceeds to step S72, in which the command isreceived and analyzed. If the result of the determination in step S71 isnegative, the process returns to the initial state.

In step S73, the CPU determines if the received command is a command tocontrol the power supply. If the result of the determination isnegative, the process proceeds to step S74, in which a controlcorresponding to the received command is executed.

If the result of the determination in step S73 is affirmative, theprocess proceeds to step S75, in which the CPU determines if thereceived command is a command to turn on the power supply oftransmission/reception block 12a. If the result of the determination isaffirmative, the process proceeds to step S76, in which signal 27 ismade to an "on" signal to switch on switch 23, whereby main power supply22 is turned on to supply electric power to data/statustransmission/reception unit 29, so that data can be transmitted to andreceived from host computer 1 and transmission/reception block 13a. Ifthe result of the determination in step S75 is negative, the processproceeds to step S77, in which the CPU determines if the receivedcommand is a command to turn off the power supply oftransmission/reception block 12a. If the result of the determination isaffirmative, the process proceeds to step S78, in which signal 27 ismade to an "off" signal to switch off switch 23, whereby main powersupply unit 22 is turned off.

If the result of the determination in step S77 is negative, that is, ifthe received command is a power-supply-on/off command fortransmission/reception block 13a or printer 14a, the process proceeds tostep S79, in which the power-supply-on/off command fortransmission/reception block 13a or printer 14a is transmitted totransmission/reception block 13a.

After the processing of step S74, S76, S78 or S79 has been completed,the process returns to step S71, and the above-described processing isrepeated.

Accordingly, the power supply of transmission/reception block 12a issubjected to on/off control in accordance with a command input from hostcomputer 1. The power supplies of transmission/reception block 13a andprinter 14a are also subjected to on/off control in accordance with thecommand input from host computer 1. Since electric power supply to therespective command transmission/reception units oftransmission/reception blocks 13a and printer 14a is maintained, thepower supply control request from host computer 1 is achieved.

FIG. 9 is a flowchart illustrating the operation of commandtransmission/reception unit 38 of transmission/reception block 13a shownin FIG. 7. The operation of command/status transmission/reception unit38 will be described with reference to the flowchart shown in FIG. 9.

In step S81, the CPU determines if a command from transmission/receptionblock 12a has been received within the RAM. If the result of thedetermination is affirmative, the proceeds to steps S82, and further toS83. If the result of the determination is negative, the process returnsto the initial state.

In step S83, the CPU determines if the received command is a powersupply control command. If the result of the determination is negative,the process proceeds to step S84. If the result of the determination isaffirmative, the process proceeds to step S85.

In step S85, the CPU determines if the received command is a command toturn on the power supply of transmission/reception block 13a. If theresult of the determination is affirmative, the process proceeds to stepS86, in which signal 36 is made to be an "on" signal to switch on switch33, whereby main power supply unit 32 is turned on to supply electricpower to data/status transmission/reception unit 37, so that data can betransmitted to and received from transmission/reception block 12a andprinter 14a. If the result of the determination in step S85 is negative,the process proceeds to step S87, in which the CPU determines if thereceived command is a command to turn off the power supply oftransmission/reception block 13a. If the result of the determination isaffirmative, the process proceeds to step S88, in which signal 36 ismade to be an "off" signal to switch off switch 33, whereby main powersupply unit 32 is turned off.

If the result of the determination in step S87 is negative, that is, ifthe received command is a power-supply-on/off command for printer 14a,the process proceeds to step S89, in which the power-supply-on/offcommand for printer 14a is transmitted to printer 14a.

After the processing of step S84, S86, S88 or S89 has been completed,the process returns to step S81, and the above-described processing isrepeated.

Accordingly, the power supply of transmission/reception block 13a issubjected to on/off control in accordance with a command input fromtransmission/reception block 12a. The power supply of printer 14a isalso subjected to on/off control in accordance with the command inputfrom transmission/reception block 12a. Since electric power supply tothe respective command transmission/reception units oftransmission/reception blocks 13a and printer 14a is maintained, thepower supply control request input via transmission/reception block 12ais achieved.

FIG. 10 is a flowchart illustrating the operation of command receptionunit 52 of printer 14a shown in FIG. 7. The operation of commandreception unit 52 will be described with reference to the flowchartshown in FIG. 10. The program shown in this flowchart is stored in theROM, and the CPU controls the following operation based on the program.

In step S91, the CPU determines if a command from transmission/receptionblock 13a has been received within the RAM. If the result of thedetermination is affirmative, the proceeds to steps S92, and further toS93. If the result of the determination is negative, the process returnsto the initial state.

In step S93, the CPU determines if the received command is a powersupply control command. If the result of the determination is negative,the process proceeds to step S94. If the result of the determination isaffirmative, the process proceeds to step S95.

In step S95, the CPU determines if the received command is a command toturn on the power supply of printer 14a. If the result of thedetermination is affirmative, the process proceeds to step S96, in whichsignal 50 is made to be an "on" signal to switch on switch 49, wherebymain power supply unit 48 is turned on to supply electric power to block40a, so that printer 14a can transmit and receive data. If the result ofthe determination in step S95 is negative, the process proceeds to stepS97, in which the CPU determines if the received command is a command toturn off the power supply of printer 14a. If the result of thedetermination is affirmative, the process proceeds to step S98, in whichsignal 50 is made to be an "off" signal to switch off switch 49, wherebymain power supply unit 48 is turned off. If the result of thedetermination in step S97 is negative, the process returns to step S91.

After the processing of step S94, S96 or S98 has been completed, theprocess returns to step S59, and the above-described processing isrepeated.

Accordingly, the power supply of printer 14a is subjected to on/offcontrol in accordance with a command input from transmission/receptionblock 13a. Since electric power supply to command reception unit 52 ofprinter 14a is maintained, the power supply control request input viatransmission/reception block 13a is achieved.

FIG. 11 is a block diagram illustrating a schematic configuration of aprinting system according to still another embodiment of the presentinvention. In FIG. 11, the same units as those shown in FIG. 7 areindicated by the same reference numerals, and an explanation thereofwill be omitted.

In this embodiment, the transmission/reception unit of each oftransmission/reception blocks 12b and 13b and printer 14b is dividedinto a data transmission/reception unit, a command/statustransmission/reception unit, and a power on/off commandtransmission/reception unit. The power supplies oftransmission/reception blocks 12b and 13b and printer 14b are subjectedto on/off control based on a power-supply-on/off command from hostcomputer 1 received via power-on/off command transmission/receptionunits 60, 62 and 64, respectively.

In FIG. 11, data from host computer 1 is transmitted to printer 14b viarespective data and command/status transmission/reception units 29a, 37aand 51a of transmission/reception blocks 12b and 13b and printer 14b,and the transmitted data is subjected to printing. When apower-supply-on/off command from host computer 1 has been received bypower-on/off command transmission/reception unit 60, power supply switch23 is switched on or off by signal 27 in accordance with the contents ofthe command, and the power-supply-on/off command is transmitted totransmission/reception block 13b via antenna 26-1 and 26-2. This commandis received by power-on/off command transmission/reception unit 62, andthe power supply of transmission/reception block 13b is turned on or offby controlling power supply switch 33 by signal 36. The command isfurther transmitted from power-on/off command transmission/receptionunit 62 to power-on/off command reception unit 64 of printer 14b,whereby the power supply of printer 14b is subjected to on/off control;

FIG. 12 is a flowchart illustrating the operation of power-on/offcommand transmission/reception unit 60 of transmission/reception block12b shown in FIG. 11. The operation of power-on/off commandtransmission/reception unit 60 will be described with reference to theflowchart shown in FIG. 12. The program shown in the flowchart of FIG.12 is stored in the ROM. The CPU controls the following operation basedon this program.

First, in step S101, the CPU determines if a power-supply-on/off commandfrom host computer 1 has been received within the RAM. If the result ofthe determination is affirmative, the process proceeds to step S102. Ifthe result of the determination in step S101 is negative, the processreturns to the initial state.

In step S102, the CPU determines if the received command is a command toturn on the power supply of transmission/reception block 12b. If theresult of the determination is affirmative, the process proceeds to stepS103, in which signal 27 is made to be an "on" signal to switch onswitch 23, whereby main power supply 22 is turned on to supply electricpower to data/command/status transmission/reception unit 29a, so thatdata can be transmitted to and received from host computer 1 andtransmission/reception block 13b. If the result of the determination instep S102 is negative, the process proceeds to step S104, in which theCPU determines if the received command is a command to turn off thepower supply of transmission/reception block 12b. If the result of thedetermination is affirmative, the process proceeds to step S105, inwhich signal 27 is made to be an "off" signal to switch off switch 23,whereby main power supply unit 22 is turned off.

If the result of the determination in step S104 is negative, that is, ifthe received command is a power-supply-on/off command fortransmission/reception block 13b or printer 14b, the process proceeds tostep S106, in which the power-supply-on/off command fortransmission/reception block 13b or printer 14b is transmitted totransmission/reception block 13b.

After the processing of step S103, S105 or S106 has been completed, theprocess returns to step S101, and the above-described processing isrepeated.

Accordingly, the power supply of transmission reception block 12b issubjected to on/off control in accordance with a command input from hostcomputer 1. The power supplies of transmission/reception block 13b andprinter 14b are also subjected to on/off control in accordance with thecommand input from host computer 1. Since electric power supply topower-on/off command reception unit 64 of printer 14b is maintained, thepower supply control request from host computer 1 is achieved.

FIG. 13 is a flowchart illustrating the operation of power-on/offcommand transmission/reception unit 62 of transmission/reception block13b shown in FIG. 11. The operation of power-of/off commandtransmission/reception unit 62 will be described with reference to theflowchart shown in FIG. 13.

In step S111, the CPU determines if a command fromtransmission/reception block 12b has been received. If the result of thedetermination is affirmative, the process proceeds to steps S112. If theresult of the determination is negative, the process returns to theinitial state.

In step S112, the CPU determines if the received command is a command toturn on the power supply of transmission/reception block 13b. If theresult of the determination is affirmative, the process proceeds to stepS113, in which signal 36 is made to be an "on" signal to switch onswitch 33, whereby main power supply unit 32 is turned on to supplyelectric power to data/command/status transmission/reception unit 37a,so that data can be transmitted to and received fromtransmission/reception block 12b and printer 14b. If the result of thedetermination in step S112 is negative, the process proceeds to stepS114, in which the CPU determines if the received command is a commandto turn off the power supply of transmission/reception block 13b. If theresult of the determination is affirmative, the process proceeds to stepS115, in which signal 36 is made to be an "off" signal to switch offswitch 33, whereby main power supply unit 32 is turned off.

If the result of the determination in step S114 is negative, that is, ifthe received command is a power-supply-on/off command for printer 14b,the process proceeds to step S116, in which the power-supply-on/offcommand for printer 14b is transmitted to printer 14b.

After the processing of step S113, S115 or S116 has been completed, theprocess returns to step S111, and the above-described processing isrepeated.

Accordingly, the power supply of transmission/reception block 13b issubjected to on/off control in accordance with a command input fromtransmission/reception block 12b. The power supply of printer 14b isalso subjected to on/off control in accordance with the command inputfrom transmission/reception block 12b. Since electric power supply topower-on/off command reception unit 64 of printer 14b is maintained, thepower supply control request input via transmission/reception block 12bis achieved.

FIG. 14 is a flowchart illustrating the operation of power-on/offcommand reception unit 64 of printer 14b shown in FIG. 11. The operationof power-on/off command reception unit 64 will be described withreference to the flowchart shown in FIG. 14. The program shown in thisflowchart is stored in the ROM, and the CPU controls the followingoperation based on the program.

In step S121, the CPU determines if a command fromtransmission/reception block 13b has been received within the RAM. Ifthe result of the determination is affirmative, the process proceeds tosteps S122. If the result of the determination is negative, the processreturns to the initial state.

In step S122, the CPU determines if the received command is a command toturn on the power supply of printer 14b. If the result of thedetermination is affirmative, the process proceeds to step S123, inwhich signal 50 is made to be an "on" signal to switch on switch 49,whereby main power supply unit 48 is turned on to supply electric powerto block 53, so that printer 14b can transmit and receive data. If theresult of the determination in step S122 is negative, the processproceeds to step S124, in which the CPU determines if the receivedcommand is a command to turn off the power supply of printer 14b. If theresult of the determination is affirmative, the process proceeds to stepS125, in which signal 50 is made to be an "off" signal to switch offswitch 49, whereby main power supply unit 48 is turned off. If theresult of the determination in step S124 is negative, the processreturns to step S121.

After the processing of step S123 or S125 has been completed, theprocess returns to step S121, and the above-described processing isrepeated.

Accordingly, the power supply of printer 14b is subjected to on/offcontrol in accordance with a command input from transmission/receptionblock 13b. Since electric power supply to power-on/off command receptionunit 64 of printer 14b is maintained, the power supply control requestinput via transmission/reception block 13b is achieved.

FIG. 15 is a block diagram illustrating a schematic configuration of aprinting system according to still another embodiment of the presentinvention. In FIG. 15, the same units as those shown in FIG. 11 areindicated by the same reference numerals, and an explanation thereofwill be omitted.

In this embodiment, the respective sub-power supply units 25, 35 and 47of transmission/reception blocks 12b and 13b and printer 14b arereplaced by batteries 61, 63 and 65, respectively.

In the printers 4, 14a and 14b of the foregoing embodiments and printer14c of the present embodiment, printing may be performed by anyrecording method. For example, these embodiments may, of course, beapplied to any of laser-beam printers, thermal transfer printers,ink-jet printers and the like.

Next, a description will be provided of a system, in which a wirenetwork system and a radio network system are mixed, according to stillanother embodiment of the present invention.

FIG. 17 is a flowchart of this embodiment illustrating the operationperformed when, as shown in FIG. 24, host computer 1 causes the powersupply of printer 14 to be started via radio transceivers 12 and 13 in asystem in which a wire network system (a system using interface cables)and a radio network system (a system using radio informationtransceivers) are mixed. The entire procedure shown in FIG. 17 iscontrolled by the CPU within host computer 1 shown in FIG. 16. Theprogram of the procedure is incorporated in the ROM within hostcomputer 1. The operation of this embodiment will be described withreference to FIG. 17.

First, in step S131, a command to start respective power supplies istransmitted from host computer 1 to transmission/reception blocks 12 and13 and printer 14. Thereafter, in step S132, host computer 1 requeststransmission blocks 12 and 13 and printer 14 to transmit respectivestatus signals, and the process proceeds to step S133. If apredetermined time period has elapsed in step S133, the process proceedsto step S134. If the predetermined time period has not elapsed in stepS133, the process returns to step S132. In step S134, the CPU checks ifa status signal to turn on the power supply has returned fromtransmission/reception block 12. If the result of the check isaffirmative, the process proceeds to step S136. If the result of thecheck is negative, the process proceeds to step S135. In step S135,since the power supply of transmission/reception block 12 is not turnedon, a display "The power supply of the transceiver is not turned on.Turn on the power supply of the printer through wire." or the like isperformed on a CRT.

In step S136, the CPU checks if a status signal to turn on the powersupply has returned from transmission/reception block 13. If the resultof the check is affirmative, the process proceeds to step S138. If theresult of the check is negative, the process proceeds to step S137, inwhich a display "The power supply of the transceiver is not turned on.Turn on the power supply of the printer through wire." or the like isperformed on the CRT. Reference numeral 2001 shown in FIG. 18 representsthe contents of the display.

Similarly, in step S138, the CPU checks if a status signal to turn onthe power supply has returned from printer 14. If the result of thecheck is affirmative, the process is terminated. If the result of thecheck is negative, the process proceeds to step S139, in which a display"The power supply of the printer is not turned on." is performed on theCRT. Reference numeral 2002 shown in FIG. 18 represents the contents ofthe display.

Accordingly, when a display to request to turn on the power supply ofeach unit through wire is performed on the CRT of host computer 1, itindicates that some kind of trouble which does not permit transmissionof a radio signal has occurred. In such a case, the user switches thesystem from the radio system to the wire system, and transmits apower-supply-on command. In the above-described display operation, acommand may be transmitted while automatically switching the system fromthe radio system to the wire system, and a display indicating that thecommand is being transmitted may be performed on the CRT.

FIG. 19 is a flowchart illustrating the operation of still anotherembodiment of the present invention. As in the above-describedembodiment, FIG. 19 illustrates the flow performed when host computer 1causes the power supply of printer 14 to be turned off via radiotransceivers 12 and 13 in the system shown in FIG. 24. As in theabove-described embodiment, the procedure shown in FIG. 19 is controlledby the CPU within host computer 1 shown in FIG. 16. The program of theprocedure is incorporated in the ROM within host computer 1. Theoperation of this embodiment will be described with reference to FIG.19.

First, in step S141, a command to turn off respective power supplies istransmitted from host computer 1 to transmission/reception blocks 12 and13 and printer 14. Thereafter, in step S142, host computer 1 requeststransmission blocks 12 and 13 and printer 14 to transmit respectivestatus signals, and the process proceeds to step S143. If apredetermined time period has elapsed in step S143, the process proceedsto step S144. If the predetermined time period has not elapsed in stepS143, the process returns to step S142. In step S144, the CPU checks ifa status signal to turn off the power supply has returned fromtransmission/reception block 12. If the result of the check isaffirmative, the process proceeds to step S146. If the result of thecheck is negative, the process proceeds to step S145. In step S145,since the power supply of transmission/reception block 12 is not turnedoff, a display "The power supply of the transceiver is not turned off.Turn off the power switch of the printer through wire." or the like isperformed on the CRT.

In step S146, the CPU checks if a status signal to turn off the powersupply has returned from transmission/reception block 13. If the resultof the check is affirmative, the process proceeds to step S148. If theresult of the check is negative, the process proceeds to step S147, inwhich a display "The power supply of the transceiver is not turned off.Turn off the power supply of the printer through wire." or the like isperformed on the CRT. Reference numeral 2003 shown in FIG. 20 representsthe contents of the display.

Similarly, in step S148, the CPU checks if a status signal to turn offthe power supply has returned from printer 14. If the result of thecheck is affirmative, the process is terminated. If the result of thecheck is negative, the process proceeds to step S149, in which the CRTdisplays "The power supply of the printer is not turned off." or thelike. Reference numeral 2004 shown in FIG. 20 represents the contents ofthe display.

Accordingly, when a display to request to turn off the power supply ofeach unit through wire is performed on the CRT of host computer 1, itindicates that some kind of trouble which does not permit transmissionof a radio signal has occurred. In such a case, the user switches thesystem from the radio system to the wire system, and transmits apower-supply-off command. In the above-described display operation, acommand may be transmitted while automatically switching the system fromthe radio system to the wire system, and a display indicating that thecommand is being transmitted may be performed on the CRT.

FIGS. 21 and 22 are flowcharts illustrating the operation of stillanother embodiment of the present invention, and illustrate theprocessing performed when data cannot favorably be transferred whentransmitting the data from host computer 1 to printer 14 via radiotransceivers 12 and 13 in the system shown in FIG. 24. The entireprocedure shown in FIGS. 21 and 22 is controlled by the CPU within hostcomputer 1. The program of the procedure is incorporated in the ROMwithin host computer 1. The operation of this embodiment will bedescribed with reference to the flowcharts shown in FIGS. 21 and 22.

First, in step S151, host computer 1 starts to transmit data to printer14, and the process proceeds to step S152. Step S152 is repeated until apredetermined time period elapses. When the predetermined time periodhas elapsed, the process proceeds to step S153. In step S153, the CPUchecks if an ACK signal has returned from printer 14 to host computer 1.If the result of the check is affirmative, the process returns to stepS152, in which after the lapse of the predetermined time period the CPUchecks again if an ACK signal has returned. If the result of the checkin step S153 is negative, the process proceeds to step S154, in whichthe CPU checks if the data transfer to printer 14 has been completed.

If the result of the check in step S154 is affirmative, the datatransfer is terminated. If the result of the check in step S154 isnegative, the process proceeds to step S155, in which the CPU requeststransmission/reception blocks 12 and 13 and printer 14 to transmitrespective status signals. The process then proceeds to step S156, inwhich the CPU checks if a predetermined time period has elapsed. If theresult of the check is affirmative, the process proceeds to step S157.If the result of the check is negative, the process returns to stepS155.

In step S157, the CPU checks if a status signal to turn on the powersupply has returned from transmission/reception block 12. If the resultof the check is affirmative, the process proceeds to step S161. If theresult of the check is negative, the process proceeds to step S158, inwhich the CPU checks if a status signal to turn off the power supply hasreturned from transmission/reception block 12. If the result of thecheck is affirmative, the process proceeds to step S159, in which adisplay "The power supply of the transceiver is turned off." or the likeis performed on the CRT of host computer 1. Reference numeral 2005 shownin FIG. 23 represents the contents of the display. If the result of thecheck in step S158 is negative, it indicates that transmission/receptionblock 12 does not operate correctly. In such a case, the processproceeds to step S160, in which a display "The transceiver does notoperate correctly." is performed on the CRT. Reference numeral 2006shown in FIG. 23 represents the contents of the display.

In step S161, the CPU checks if a status signal to turn on the powersupply has returned from transmission/reception block 13. If the resultof the check is affirmative, the process proceeds to step S164. If theresult of the check is negative, the process proceeds to step S162, inwhich the CPU checks if a status signal to turn off the power supply hasreturned from transmission/reception block 13. If the result of thecheck is affirmative, the process proceeds to step S163, in which adisplay "The power supply of the transceiver is turned off." or the likeis performed on the CRT. If the result of the check in step S162 isnegative, the process proceeds to step S167, in which a display "Datacannot be transferred to the printer by wireless transmission." or thelike is performed on the CRT, since communication cannot be performedwith transmission/reception block 13. Reference numeral 2008 shown inFIG. 23 represents the contents of the display.

In step S164, the CPU checks if a status signal to turn on the powersupply has returned from printer 14. If the result of the check isaffirmative, the process proceeds to step S167. If the result of thecheck is negative, the process proceeds to step S165, in which the CPUchecks if a status signal to turn off the power supply has returned fromprinter 14. If the result of the check is negative, the process proceedsto step S167. If the result of the check is affirmative, the processproceeds to step S166, in which a display "The power supply of theprinter is turned off." or the like is performed on the CRT. Referencenumeral 2007 shown in FIG. 23 represents the contents of the display.

In the above-described embodiment, information, comprising commands andthe like, is output to the printer while switching the system from theradio system to the wire system. However, information may be outputwhile switching the system from the wired system to the radio system.

FIG. 25 is a block diagram illustrating the configuration of control ofan apparatus according to still another embodiment of the presentinvention.

In FIG. 25, reference numeral 3000 represents a printing apparatus.Control unit 3002 is configured by a CPU, a ROM, a RAM and the like (notshown), and includes an input unit 3004 for receiving input data, suchas control codes and the like, from an external apparatus (for example,host computer 1), a control-code analysis unit 3005 for analyzingcontrol codes and the like in the received input data, output unit 3006for generating an image signal to be output to output mechanism 3009based on a control code output from control-code analysis unit 3005, andthe like. Data-input detection unit 3007 detects data input from hostcomputer 1, and transmits a command to power-supply control unit 3008 tosupply control unit 3002 and output mechanism 3009 with current Powersupply unit 3010 supplies control unit 3002 and output mechanism 3009with electric power having a predetermined potential. Output mechanism3009 prints a document or an image on recording medium 3011 based onprinting information (for example, a laser-on/off signal when using alaser-beam printer engine) from output unit 3006. Electric power supplyis maintained for data-input detection unit 3007 and power-supplycontrol unit 3008 from a power supply unit (not shown) which isdifferent from power supply unit 3010.

A description will now be provided of the configuration and theoperation of each unit.

Data transferred from host computer 1 is first stored in input unit3004, comprising a RAM and the like (not shown), and is then transmittedto control-code analysis unit 3005. When control-code analysis unit 3005analyzes that the input data comprises a control code corresponding topower supply control, it transmits to power-supply control unit 3008 acommand to turn off electric power supply for at least one of controlunit 3002 and output mechanism 3009 of printing apparatus 3000.Power-supply control unit 3008 interrupts current supply from powersupply unit 3010 to at least one of control unit 3002 and outputmechanism 3009 based on the command received from control-code analysisunit 3005. In the case of another control code, control-code analysisunit 3005 transmits a processing command relating to an output operationto output unit 3006. Output unit 3006 performs, for example, on/offcontrol of a laser beam for output mechanism 3009, whereby a printingresult is recorded on recording medium 3011, such as paper or the like.

In the printing apparatus having the above-described configuration,control-code analysis unit 3005 analyzes an input code from hostcomputer 1, and power-supply control unit 3008 interrupts electric powersupply from power supply unit 3010 to at least one of control unit 3002and output mechanism 3009 according to the operation program (stored ina ROM (not shown)) shown in the flowchart of FIG. 26 (to be describedlater). Hence, it is possible to securely interrupt electric powersupply to at least one of control unit 3002 and output mechanism 3009 ofprinting apparatus 3000 by a command from host computer 1.

In still another embodiment of the present invention, data-inputdetection unit 3007 monitors a data input state for a predetermined timeperiod, and outputs a power-supply control command for interruptingelectric power supply from power supply unit 3010 to at least one ofcontrol unit 3002 and output mechanism 3009 to power-supply control unit3008. Power-supply control unit 3008 thereby interrupts electric powersupply from power supply unit 3010 to at least one of control unit 3002and output mechanism 3009 according to the flowchart shown in FIG. 27(to be described later). Hence, it is possible to securely interruptelectric power supply to output mechanism 3009 or control unit 3002having a large loss in electric power even if a printing waiting stateis provided for a long time period after printing processing has beenperformed, and to reduce electric power consumption in the entireprinting apparatus.

In still another embodiment of the present invention, data-inputdetection unit 3007 detects a data input from host computer 1 whileelectric power supply to control unit 3002 is interrupted, and outputs apower-supply control command for starting electric power supply frompower supply unit 3010 to at least one of control unit 3002 and outputmechanism 3009. Power-supply control unit 3008 thereby starts electricpower supply from power supply unit 3010 to at least one of control unit3002 and output mechanism 3009 according to the flowchart shown in FIG.28 (to be described later). Hence, it is possible securely startelectric power supply to control unit 3002 or output mechanism 3009 ofprinting apparatus 3000 only by outputting data from host computer 1 toprinting apparatus 3000, and to reduce electric power consumption in theentire printing apparatus.

In the above-described flow of processing, when data has not beentransmitted from host computer 1 to input unit 3004 for at least apredetermined time period, control-code analysis unit 3005 terminatesanalysis and transmits a command to interrupt electric power supply toat least one of control unit 3002 and output mechanism 3009 of printingapparatus 3000 to power-supply control unit 3008. Power-supply controlunit 3008 interrupts electric power supply from power supply unit 3010to at least one of control unit 3002 and output mechanism 3009 based onthe command received from control-code analysis unit 3005.

When data has been transmitted from host computer 1 while electric powersupply to control unit 3002 of printing apparatus 3000 has beeninterrupted, data-input detection unit 3007 detects the data input andtransmits a command to supply electric power to at least one of controlunit 3002 and output mechanism 3009 to power-supply control unit 3008,and instructs control unit 3002 to start a data input operation.Power-supply control unit 3008 causes electric power supply from powersupply unit 3010 to at least one of control unit 3002 and outputmechanism 3009 based on the command received from data-input detectionunit 3007. A description will now be provided of a power-supply controlprocedure in the printing apparatus of the present invention withreference to the flowcharts shown in FIGS. 26 through 28.

FIG. 26 is a flowchart illustrating a power-supply control procedure inthe printing apparatus of the present invention. Steps S151-S159indicate respective steps in the procedure. The control procedure isstored in a ROM within power-supply control unit 3008 comprising a CPUand the like.

When data is transmitted from host computer 1, a control code in thedata is analyzed in step S151. If the control code is determined to be acontrol code relating to power-supply control in step S152, the analysisis terminated (step S154), and end processing is performed in step S156.In step S157, the CPU determines if electric power supply to controlunit 3002 must be interrupted based on the control code. If the resultof the determination is affirmative, electric power supply to controlunit 3002 is interrupted, and the process proceeds to step S159. If theresult of the determination is negative, electric power supply to outputmechanism 3009 is interrupted (step S159), and the process isterminated.

If the result of the determination in step S152 is negative, processingrelating to an output operation is performed (step S153), and the CPUdetermines if the analysis has ended (step S155). If the result of thedetermination is negative, the process returns to step S151. If theresult of the determination is affirmative, the process proceeds to stepS156, in which end processing is performed.

The control operation to interrupt electric power supply to at least oneof control unit 3002 and output mechanism 3009 of printing apparatus3000 when data has not been transmitted from host computer 1 for atleast a predetermined time period will now be described in detail.

FIG. 27 is a flowchart illustrating another power-supply controlprocedure in the printing apparatus of the present invention. StepsS161-S169 indicate respective steps of the procedure. The controlprocedure is stored in the ROM within power-supply control unit 3008comprising the CPU and the like.

First, the CPU determines if data has not been transmitted from hostcomputer 1 for at least a predetermined time period based on thedetection state of input data by data-input detection unit 3007 (stepS161). If the result of the determination is affirmative, processing ofanalyzing a control code is terminated (step S164), and the processproceeds to step S166, in which end processing is performed. In stepS167, the CPU determines if electric power supply to control unit 3002must be interrupted. If the result of the determination is affirmative,electric power supply to control unit 3002 is interrupted in step S168,and the process proceeds to step S169. If the result of thedetermination is negative, electric power supply to output mechanism3009 is interrupted (step S169), and the process is terminated.

If the result of the determination in step S161 is negative,control-code analysis unit 3005 analyzes the control code transmittedfrom host computer 1 to input unit 3004 (step S162). After performingprocessing relating to an output operation (step S163), the CPUdetermines if the analysis has ended (step S165). If the result of thedetermination is negative, the process returns to step S161. If theresult of the determination is affirmative, the process proceeds to stepS166, in which end processing is performed.

The control operation to cause electric power supply to at least one ofcontrol unit 3002 and output mechanism 3009 of printing apparatus 3000when input data has been received from host computer 1 in a state inwhich electric power supply is interrupted will now be described indetail.

FIG. 28 is a flowchart illustrating still another power-supply controlprocedure in the printing apparatus of the present invention. StepsS171-S177 indicate respective steps in the procedure. The controlprocedure is stored in ROM's provided within power-supply control unit3008 and data-input detection unit 3007, each comprising a CPU, acontrol circuit and the like.

When data-input detection unit 3007 has detected that data has beentransmitted from host computer 1 while electric power supply to controlunit 3002 of printing apparatus 3000 has been interrupted (step S171),the CPU determines if the transmitted data comprises a command to turnoff the power supply (step S172). If the result of the determination isnegative, power-supply control unit 3008 controls power supply unit 3010so as to supply electric power to control unit 3002 (step S173), andalso to output mechanism 3009 (step S174). There after, processingrelating to an output operation is performed (step S175), and theprocess is terminated. If the result of the determination in step S172is affirmative, host computer 1 is notified that the power supply isalready turned off (step S176), the transmitted data is skipped (stepS177), and the process is terminated.

In the above-described embodiments, means to turn off the power supplyaccording to a control code and when data has not been transmitted forat least a predetermined time period may be applied not only to theoutput mechanism (laser printing mechanism) shown in the embodiments,but also to a printing apparatus including any other printer engine,such as an ink-jet printer engine, a dot-matrix printer engine or thelike.

The apparatus to which the fact that the power supply is turned off isnotified is not limited to an external apparatus, but may be a displayunit (a panel or a buzzer) of the printing apparatus. Alternatively, thefact may not be notified.

Any units other than control unit 3002 and output mechanism 3009 may beincluded in the units for which electric power supply is controlled.Alternatively, the power supply of output mechanism 3009 may be turnedon or off prior to control unit 3002. Thereafter, the power supply ofcontrol unit 3002 may be turned on or off after the lapse of apredetermined time period. In another approach, the power supply may notbe controlled.

Output mechanism 3009 is not limited to the above-described one. Forexample, an original-feeding device for performing pre-processing ofsheets which can be optionally connected, a sorter device for performingpost-processing of sheets, and the like may be adopted as outputmechanisms. By performing electric power supply control while combiningsuch devices with the above-described units to be controlled, it ispossible to provide a printing apparatus having a high efficiency ofelectric power consumption.

Data to instruct interruption of electric power supply from hostcomputer 1 is not limited to a dedicated control command, but may haveany other data format.

FIG. 30 is a cross-sectional view illustrating the configuration of alaser-beam printer to which any of the above-described embodiments canbe applied. The printer is configured such that character patterns andform data can be registered from a data source (not shown).

In FIG. 30, reference numeral 1000 represents a main body of alaser-beam printer (LBP) (hereinafter simply termed a "main body"). Mainbody 1000 inputs and stores character information (character codes),form information, macrocommands and the like supplied from an externalapparatus connected thereto, such as host computer 1 shown in FIG. 1, orthe like, forms character patterns, a form pattern and the like, whichcorrespond to the information, in accordance with the information, andforms an image on recording paper, serving as a recording medium.Operation panel 1112 includes switches for various operations, and anLED (light-emitting diode) display unit or an LCD (liquid-crystaldisplay) unit for displaying the state of the printer. Printer controlunit 1101 controls the entire LBP 1000, and analyzes characterinformation and the like supplied from host computer 1. Printer controlunit 1101 mainly converts character information into a video signalrepresenting corresponding character patterns, and outputs the signal tolaser driver 1102. Laser driver 1102 is a circuit for drivingsemiconductor laser 1103, and performs on/off control of laser light1104 emitted from semiconductor laser 1103 in accordance with the inputvideo signal. An electrostatic latent image of character patterns isthereby formed on electrostatic drum 1106.

This latent image is developed by developing unit 1107 provided aroundelectrostatic drum 1106, and the developed image is transferred ontorecording paper. The recording paper comprises cut sheets, which areaccommodated within sheet cassette 1108 mounted in main body 1000. Eachsheet is fed into the apparatus by sheet-feeding roller 1109 andconveying rollers 1110 and 1111, and is supplied to electrostatic drum1106.

FIG. 31 is an external view illustrating the configuration of a printingapparatus to which any of the above-described embodiments can beapplied, and illustrates an ink-jet recording apparatus (IJRA).

In FIG. 31, carriage HC which engages with helical groove 5004 of leadscrew 5005 rotating via driving-force transmission gears 5011 and 5009in accordance with the forward or reverse rotation of driving motor 5013includes a pin (not shown), and is reciprocated in the directions ofarrows a and b. Ink-jet cartridge IJC is mounted on carriage HC.Sheet-pressing plate 5002 presses the sheet of recording paper againstplaten 5000 along the moving direction of carriage HC. Photocouplercomponents 5007 and 5008 serve as home-position detection means forconfirming the presence of lever 5006 of carriage HC in the region ofthese components, and performing, for example, switching of thedirection of rotation of driving motor 5013. Member 5016 supports capmember 5022 which caps the front surface of the recording head.Reference numeral 5015 represents suction means for sucking the insideof the cap, which performs a suction recovery operation of the recordinghead via opening 5023 of the cap. Cleaning blade 5017 can be moved backand forth by member 5019. Supporting plate 5018 of the main body of theapparatus supports cleaning blade 5017 and member 5019. Referencenumeral 5012 represents a lever for starting suction for a suctionrecovery operation, which moves in accordance with the movement of cam5020, which engages with carriage HC. The driving force of driving motor5013 is transmitted by known transmission means, such as a clutch or thelike, to move lever 5012.

The apparatus is configured so that each of the above-described capping,cleaning and suction recovery operations is performed at thecorresponding position by the function of lead screw 5005 when carriageHC reaches the region of the home-position side. These operations can beperformed provided that a desired operation is performed with anappropriate timing.

The present invention may be applied to a system comprising a pluralityof apparatuses, or to an apparatus comprising a single unit. The presentinvention may, of course, be applied to a case in which the invention isachieved by supplying a system or an apparatus with a program to executethe invention.

The individual components shown in outline or designated by blocks inthe drawings are all well-known in the printing apparatus andinformation processing apparatus arts and their specific constructionand operation are not critical to the operation or best mode forcarrying out the invention.

While the present invention has been described with respect to what ispresently considered to be the preferred embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. To the contrary, the present invention is intended to covervarious modifications and equivalent arrangements included within thespirit and scope of the appended claims. The scope of the followingclaims is to be accorded the broadest interpretation so as to encompassall such modifications and equivalent structures and functions.

What is claimed is:
 1. An image processing apparatus comprising:imagedata receiving means for receiving image data sent from an image datasource; command data receiving means for receiving command data sentfrom the image data source; first supply means for controllablysupplying said image data receiving means with power from a powersource; second supply means for supplying said command data receivingmeans with power from the power source, said first supply means beingcontrollable independently of said second supply means; processing meansfor performing image processing on the received image data; and controlmeans for controlling said first supply means to supply power to atleast said image data receiving means, wherein in a case that saidcommand data receiving means receives a power-on command, said controlmeans controls said first supply means to supply power to said imagedata receiving means in accordance with the received power-on command.2. An apparatus according to claim 1, further comprising the powersource, said power source having a first power source element forsupplying power to said first supply means for at least said image datareceiving means and a second power source element for supplying power tosaid second supply means for at least said command receiving means. 3.An apparatus according to claim 2, wherein said first power sourceelement further supplies power to the image data source and to saidprocessing means.
 4. An apparatus according to claim 2, furthercomprising means for transmitting status data to the image datasource,wherein when said first power source element cannot supply power,said status data transmitting means transmits status data representingthat the first power source cannot supply power.
 5. An apparatusaccording to claim 1, wherein the received image data includes controlcodes and character codes, and said processing means comprises means foranalyzing the control codes.
 6. An apparatus according to claim 1,wherein said processing means comprises means for forming an image inaccordance with the received image data.
 7. An apparatus according toclaim 1, wherein in a case that said command receiving means receives apower-off command, said control means controls said first supply meansto stop the supply of power to said image data receiving means inaccordance with the power-off command.
 8. An image processing method inan image processing apparatus, comprising:a step of receiving image datasent from an image data source using an image data receiving means; astep of receiving command data sent from the image data source using acommand data receiving means; a first supply step of controllablysupplying the image data receiving means with power from a power source;a second supply step of supplying the command data receiving means withpower from the power source, said first supply step being controllableindependently of said second supply step; a step of performing imageprocessing on the received image data; and a step of controlling saidfirst supply step to supply power to at least the image receiving means,wherein in a case that said command data receiving step receives apower-on command, said control step controls said first supply step tosupply power to the image data receiving means in accordance with thereceived power-on command.
 9. A method according to claim 8, wherein theimage processing apparatus includes the power source, the power sourcehaving a first power source element for supplying power for said firstsupply step for at least the image data receiving means and a secondpower source element for supplying power for said second supply step forat least the command receiving means.
 10. A method according to claim 9,further comprising a step of transmitting status data to the image datasource,wherein when the first power source element cannot supply power,said status data transmitting step transmits status data representingthat the first power source cannot supply power.
 11. A method accordingto claim 8, wherein said processing step comprises a step of forming animage in accordance with the received image data.
 12. An image datagenerating apparatus comprising:means for transmitting image data to animage processing apparatus that includes image data receiving means anda first power source for supplying power to the image data receivingmeans; means for transmitting command data to the image processingapparatus, wherein a power-on command designating a start of supply ofpower to the image data receiving means may be transmitted by saidcommand data transmitting means; means for receiving status data sentfrom the image processing apparatus indicative of a condition of theimage processing apparatus; and control means for displaying conditionof data of the image processing apparatus on a display unit inaccordance with the received status data, wherein when said status datareceiving means receives status data representing that the first powersource cannot supply power, said control means displays on the displayunit condition data showing that the first power source cannot supplypower.
 13. An apparatus according to claim 12, wherein a power-offcommand for designating a stop of supply of power to the image datareceiving means may be transmitted by said data transmitting means. 14.A method for reducing a power consumption for an image processingapparatus, the image processing apparatus having means for receivingimage data sent from an image data source and means for performing animage processing on the received image data, the method comprising thesteps of:discriminating when power-on command data is received from theimage data source by command data receiving means different from theimage data receiving means; and causing supply of power to the imagedata receiving means when power is not supplied to the image datareceiving means and the command data receiving means discriminates thatpower-on command data has been received.
 15. A method according to claim14, further comprising a step of transmitting status data representingthat the power cannot be supplied to the image data receiving means whenthe power on command data is received and power cannot be supplied tothe image data receiving means.
 16. A method according to claim 14,wherein the processing means comprises means for forming an image inaccordance with the received image data, and a power supply to the imageforming means is controlled in said causing step.
 17. A method accordingto claim 14, further comprising a step of discriminating when power-offcommand data is received from the image data source by the command datareceiving means, and a step of causing shutting off of the power supplyto the image data receiving means when the power is supplied to theimage data receiving means and power-off command data has been received.18. An image processing method of transmitting print data and controlcommand data using first and second channels respectively, comprisingthe steps of:discriminating whether print data transmission using thefirst channel is prohibited or allowed on the basis of the controlcommand data transmitted through the second channel, and prohibiting orallowing print data transmission through the first channel on the basisof a result in the discrimination.
 19. A method according to claim 18,wherein print data transmission through the first channel is prohibitedor allowed according to a state of power supply to a print datareceiving means.
 20. A method according to claim 18, wherein saiddiscriminating step is executed in response to reception of the controlcommand data which requests a print data receiving apparatus to be in aprint data receivable state.
 21. A method according to claim 20, furthercomprising a step of transmitting status data representing that theprint data transmission is prohibited to a print data transmittingapparatus when it is discriminated in said discriminating step that theprint data transmission is prohibited.
 22. A method of transmittingprint data through a first channel, comprising the steps of:transmittingcontrol command data which requests a print data receiving apparatus tobe in a print data receivable state, using a second channel differentfrom the first channel for print data transmission when said print datareceiving apparatus is not in the print data receivable state, anddiscriminating whether or not print data is transmitted on the basis ofstatus data indicative of the state of said print data receivingapparatus, which is sent back from said print data receiving apparatusin response to the control command data transmitted in said transmittingstep.
 23. A method according to claim 22, wherein the control commanddata requesting said print data receiving apparatus to be in the printdata receivable state is a control command requesting power supply to atleast print data receiving means of said print data receiving apparatus.24. A method according to claim 22, further comprising a step ofdisplaying that transmission of print data is prohibited when the statusdata represents that said print data receiving apparatus is not in theprint data receivable state.
 25. A method of receiving print data andcontrol command data to be transmitted using first and second channels,respectively, comprising the steps of:discriminating whether or not thereceived control command data through the second channel requests to bein a print data receivable state when the control command data isreceived during a print data unreceivable state, and prohibiting orallowing print data transmission on the basis of a result in thediscrimination.
 26. A method according to claim 25, wherein thetransmission of print data is prohibited or allowed according to a stateof power supply to a print data receiving means.
 27. A method accordingto claim 25, further comprising a second step of discriminating whetherthe print data receivable state can be set or not, and a step oftransmitting status data representing that print data transmission isprohibited to print data transmitting apparatus when it is discriminatedin said second discriminating step that the print data receivable statecannot be set.
 28. A transmission system for transmitting print data andcontrol command data using first and second channels, respectively,comprising:means for discriminating whether print data transmissionusing the first channel is prohibited or allowed on the basis of thecontrol command data transmitted through the second channel, and meansfor prohibiting or allowing print data transmission through the firstchannel on the basis of a result in the discrimination.
 29. Atransmission system according to claim 28, wherein the prohibition orallowing means prohibits or allows print data transmission through thefirst channel according to a state of power supply to print datareceiving means.
 30. A transmission system according to claim 28,wherein the discriminating means discriminates whether the print datatransmission is prohibited or allowed in response to reception of thecontrol command data requesting a print data receiving apparatus to bein a print data receivable state.
 31. A transmission system according toclaim 30, further comprising means for transmitting status datarepresenting that print data transmission is prohibited to print datatransmitting apparatus when said discriminating means discriminates thatthe print data transmission is prohibited.
 32. A print data transmittingapparatus for transmitting print data through a first channel,comprising:means for transmitting control command data requesting aprint data receiving apparatus to be in a print data receivable stateusing a second channel different from the first channel for print datatransmission when said print data receiving apparatus is not in a printdata receivable state; means for receiving status data indicative of astate of said print data receiving apparatus, which is sent back fromsaid print data receiving apparatus in response to the control commanddata transmitted by said transmitting means; and means fordiscriminating whether print data is transmitted or not on the basis ofthe received status data.
 33. A print data transmitting apparatusaccording to claim 32, wherein the control command data requesting saidprint data receiving apparatus to be in the print data receivable stateis a control command requesting power supply to at least print datareceiving means of said print data receiving apparatus.
 34. A print datatransmitting apparatus according to claim 32, further comprising meansfor displaying that the print data transmission is prohibited, when thereceived status data represents that said print data receiving apparatusis not in the print data receivable state.
 35. A print data receivingapparatus for receiving print data transmitted through a first channel,comprising:means for receiving control command data which is transmittedusing a second channel different from the first channel for transmittingprint data; means for discriminating whether or not the received controlcommand data requests a print data receiving apparatus to be in a printdata receivable state; and means for prohibiting or allowing print datatransmission on the basis of a result in the discrimination.
 36. A printdata receiving apparatus according to claim 35, wherein the prohibitionor allowing means prohibits or allows the print data transmissionaccording to a state of the power supply of print data receivingapparatus.
 37. A print data receiving apparatus according to claim 35,further comprising second discriminating means for discriminatingwhether said print data receiving apparatus can be in the print datareceivable state or not and means for transmitting status datarepresenting that the print data transmission is prohibited to a printdata transmitting apparatus when said discriminating means discriminatesthat said print data receiving means cannot be in the print datareceivable state.